16318821 has 4 divisors (see below), whose sum is σ = 21758432. Its totient is φ = 10879212.

The previous prime is 16318811. The next prime is 16318847. The reversal of 16318821 is 12881361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16318821 - 2⁵ = 16318789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16318811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2719801 + ... + 2719806.

It is an arithmetic number, because the mean of its divisors is an integer number (5439608).

Almost surely, 2^16318821 is an apocalyptic number.

It is an amenable number.

16318821 is a deficient number, since it is larger than the sum of its proper divisors (5439611).

16318821 is an equidigital number, since it uses as much as digits as its factorization.

16318821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5439610.

The product of its digits is 2304, while the sum is 30.

The square root of 16318821 is about 4039.6560497151. The cubic root of 16318821 is about 253.6469198796.

The spelling of 16318821 in words is "sixteen million, three hundred eighteen thousand, eight hundred twenty-one".